The Dawn mission revolves around the exploration of Vesta and Ceres, the two largest known asteroids in our solar system. The Dawn spacecraft entered orbit around Vesta in July of 2011, departed in September 2012, and has been making its way for Ceres ever since, with a scheduled orbital insertion date of February 2015. In doing so, Dawn will become the first spacecraft to orbit two different solar system bodies (excepting Earth, of course). In this great little video, Leonard Nimoy joins NASA researchers in explaining what kind of science is underway aboard the Dawn spacecraft, and what lies ahead for the intrepid little ion-thrusting orbiter. Oh, did I forget to mention? Dawn is also also the first purely exploratory mission in history to make use of ion propulsion. Yes, Dawn has ION PROPULSION ENGINES. Three of them, to be exact. To reiterate: Dawn brings the awesome.